$(document).ready(function() {  
  $('form').submit(function() {  
    if(typeof jQuery.data(this, "disabledOnSubmit") == 'undefined') {  
      jQuery.data(this, "disabledOnSubmit", { submited: true });  
      $('input[type=submit], input[type=button]', this).each(function() {  
        $(this).attr("disabled", "disabled");  
      });  
      return true;  
    }  
    else  
    {  
      return false;  
    }  
  });  
}); 